对数分布

In view of the existing situation that forest tree heritabilities is estimated too extensively, the paper elaborated the effect of non normal distributions (citing the normal logarithmic distribution and Γ distribution as instances) on estimating heritabilities with simulated data.

针对林木遗传力估算过于粗放的情况，该文以对数正态分布和Γ-分布为例，应用模拟数据阐述了非正态分布对林木遗传力估算的影响。

In this paper, EM algorithm is used to estimate the parameters of exponential distribution, Weibull distribution and lognormal distribution based on randomly right censored data.

本文将EM算法用于随机右删失数据下指数分布、Weibull分布和对数正态分布的参数估计中。

Using inverse function to generate exponential distribution random number, introduce new algorithm, namely Maclaurin Equation, which is easy to be implemented by Hardware, use Maclaurin Equation to extend the function of Logarithm, make it compose by addition, division and multiple.

对于反函数法产生指数分布的随机数，提出易于硬件实现的算法结构——麦克劳林展开法，先用麦克劳林展开式展开对数函数，把对数函数转换成一系列乘、加、除运算。

Furthermore, the kernel density estimation, a nonparametric method, is used to estimate the density functions of natural logarithm of average cost per stay and average days of inpatient.

此外，本文将非参数模型中的核密度估计方法应用于每次住院费用对数和每次住院天数对数的分布研究中，并用它进一步估计了每次住院费用和每次住院天数的均值和方差，取得了较好的效果。

The soil pH, CEC and organic matter content ranged from 7.7 to 8.6, 11.9 to 28.7 cmolkg^(-1), and 3.0 to 27.9 gkg^(-1), and followed normal distribution, log-normal distribution, and negative binomial distribution, respectively. These three properties were significantly affected by land use type, landform, and soil type.

结果表明：黄土高原小流域土壤pH、CEC和有机质分别介于7.7~8.6、11.9~28.7cmolkg^(-1)和3.0~27.99kg^(-1)，分别服从正态分布、对数正态分布和负二项分布。3种土壤性质随地形、土地利用方式和土壤类型的不同差异很大。

In this paper,flood magnitude corresponding to any return period was estimated and analysed using statistical distribution wayse.g.Extreme Value(EVdistribution,Pearson TypeⅢdistribution and three-par...

以淮河王家坝水文站年最大洪峰流量系列为例，应用电子表格，采用极值分布、皮尔逊Ⅲ型分布和三参数对数正态分布等多种洪水频率分析方法进行洪水频率计算并加以对比研究，得出该站的不同重现期的洪峰流量，以供广大水文工作者参考。

Because of its easily calculating and its accurately description parametric method has became mainstream in study field, polynomial hazard function distribution model was a large class of parametric models, when the dates are not readily handled by one of the common models such as exponential distribution or Weibull distribution, polynomial hazard function model always be used to provide adequate fits of the dates.

随着该学科的发展，大量参数、非参数方法相继提出，特别是生存分析的参数方法，以其处理简便、描述准确成为生存分析研究的主流方向。多项式危险函数模型是参数模型中的一大类，当一批数据不能用熟知的一些分布，诸如Weibull分布、对数正态分布进行很好的描述时，常常使用多项式危险函数模型。

For exponential distribution, the acquired estimate expression is the same as the result obtained by other method in reference [8]; for Weibull distribution, the author prove that γ satisfies a non-linear equation and λ is afunction of y; for lognormal distribution, a iterative algorithm for parameter estimation is proposed, which is the expansion of some results in Wolynetzs Ph.D. thesis.

对指数分布，得到的估计表达式与文献[8]中使用其他方法得到的结果相同；对Weibull分布，论文证明了参数γ满足一个非线性方程，而λ则可以直接由含有γ的表达式求出；对对数正态分布，论文给出参数估计的迭代算法，这可以看成是Wolynetz博士论文结果的推广。

The quantity computed is the expected clutter power at the output of any specified range gate by the method of integrating reflected energy between constant Doppler loci in range-gate circles with a model of sum and difference antenna gain pattern for APAR. Base on the analyzing of APAR terrain clutter spectrum, Rayleigh, Correlated Log-Normal and Weibull distribution terrain clutter of APAR general pulse signal was simulated with the method of zero memory nolinearity transform.④The Doppler frequency of target echo is simulated on video frequency in this dissertation.

该软件采用了用C语言建立框架结构，而在程序高重复部分和有运算速度要求的地方，用汇编语言编写具有高并行能力程序的方法，不仅满足了系统高运算速度和实时性的要求，也使得软件系统结构模块化，代码具有良好的维护性和重用性；③对机载相控阵雷达HPRF、MPRF的和、差通道地面杂波功率谱进行了较为全面的研究，通过建立由四个子波束构成的机载相控阵雷达杂波和差波束天线方向图数学模型，选取体现高度线杂波的修正的地面后向散射模型，以载机平飞为例，采用沿距离门——等多普勒线区域积分的方法，得到了杂波功率谱，并利用零记忆非线性变换法实现了机载相控阵雷达常规脉冲情况下瑞利分布、对数正态分布和韦布尔分布地面杂波的模拟；④提出了采用在视频上对目标回波的多普勒频率进行模拟的方法。

To verify the accuracy of CFD simulations, experiments were carried out. The results of simulations with user defined function of the effects of impeller type and stirring rate on the velocity field were in good agreement with the output of particle image velocity. The oxygen mass transfer model can be used to predict the process of oxygen mass transfer in a vessel, and the logarithmical expression can successfully describe the relation between the oxygen concentration and the dissolution time.

结果表明，(1)采用Fluent软件并结合用户自定义方程(user defined function， UDF)能够很好地模拟出实际搅拌器内流场分布，模拟结果与采用粒子成像技术(particle image velocity， PIV)的实验测量结果相符；(2)采用氧气传质模型能预测氧气在搅拌器内的动态传质过程，同时氧气浓度与溶解时间的对数关系式能较好描述试验搅拌器内氧气动态传质过程；(3)在相同搅拌速度下，圆盘涡轮式搅拌器产生的湍流动能分布范围要大于桨式搅拌器产生的湍流动能，而且湍流动能分布更均匀，湍流强度更大。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。